[PATCH v1] drm/xe/gt: Introduce runtime suspend/resume
Daniele Ceraolo Spurio
daniele.ceraolospurio at intel.com
Wed Aug 20 22:25:14 UTC 2025
On 8/19/2025 4:35 AM, Raag Jadav wrote:
> If power state is retained between suspend/resume cycle, we don't have
> to perform full gt re-initialization. Introduce runtime helpers for gt
> which greatly reduces suspend/resume delay.
>
> Originally-by: Riana Tauro <riana.tauro at intel.com>
> Signed-off-by: Raag Jadav <raag.jadav at intel.com>
> ---
> drivers/gpu/drm/xe/xe_gt.c | 50 ++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/xe/xe_gt.h | 2 ++
> drivers/gpu/drm/xe/xe_guc.c | 16 +++++++++++
> drivers/gpu/drm/xe/xe_guc.h | 2 ++
> drivers/gpu/drm/xe/xe_guc_ct.c | 13 ++++++---
> drivers/gpu/drm/xe/xe_guc_ct.h | 1 +
> drivers/gpu/drm/xe/xe_pm.c | 4 +--
> drivers/gpu/drm/xe/xe_uc.c | 19 +++++++++++++
> drivers/gpu/drm/xe/xe_uc.h | 2 ++
> 9 files changed, 103 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
> index a3397f04abcc..19919760da00 100644
> --- a/drivers/gpu/drm/xe/xe_gt.c
> +++ b/drivers/gpu/drm/xe/xe_gt.c
> @@ -943,6 +943,32 @@ int xe_gt_suspend(struct xe_gt *gt)
> return err;
> }
>
> +int xe_gt_runtime_suspend(struct xe_gt *gt)
> +{
> + unsigned int fw_ref;
> + int err = -ETIMEDOUT;
> +
> + xe_gt_dbg(gt, "runtime suspending\n");
> + xe_gt_sanitize(gt);
This call to xe_gt_sanitize is a bit confusing. Historically on i915 the
gt_sanitize call implied a full reset of the GT state, which is
something we don't want to do during runtime suspend/resume (but we do
want during full D3 cold suspend). However, the current Xe
implementation of xe_gt_sanitize only sets GuC submission to disabled.
To be safe, I would suggest dropping this xe_gt_sanitize call from here
and set the GuC submission state to disabled from within the
xe_guc_pause path (which you're already doing). That way if more state
cleaning is added to gt_sanitize it won't impact this code. I'd argue we
should probably get completely rid of xe_gt_sanitize and replace it with
a GuC submission specific function if it is the only thing it touches,
but that's outside the scope of your change.
> +
> + fw_ref = xe_force_wake_get(gt_to_fw(gt), XE_FORCEWAKE_ALL);
> + if (!xe_force_wake_ref_has_domain(fw_ref, XE_FORCEWAKE_ALL))
> + goto err_msg;
> +
> + xe_uc_runtime_suspend(>->uc);
> +
> + xe_force_wake_put(gt_to_fw(gt), fw_ref);
> + xe_gt_dbg(gt, "runtime suspended\n");
> +
> + return 0;
> +
> +err_msg:
> + xe_force_wake_put(gt_to_fw(gt), fw_ref);
> + xe_gt_err(gt, "runtime suspend failed (%pe)\n", ERR_PTR(err));
> +
> + return err;
> +}
> +
> void xe_gt_shutdown(struct xe_gt *gt)
> {
> unsigned int fw_ref;
> @@ -1002,6 +1028,30 @@ int xe_gt_resume(struct xe_gt *gt)
> return err;
> }
>
> +int xe_gt_runtime_resume(struct xe_gt *gt)
> +{
> + unsigned int fw_ref;
> + int err = -ETIMEDOUT;
> +
> + xe_gt_dbg(gt, "runtime resuming\n");
> + fw_ref = xe_force_wake_get(gt_to_fw(gt), XE_FORCEWAKE_ALL);
> + if (!xe_force_wake_ref_has_domain(fw_ref, XE_FORCEWAKE_ALL))
> + goto err_msg;
> +
> + xe_uc_runtime_resume(>->uc);
> +
> + xe_force_wake_put(gt_to_fw(gt), fw_ref);
> + xe_gt_dbg(gt, "runtime resumed\n");
> +
> + return 0;
> +
> +err_msg:
> + xe_force_wake_put(gt_to_fw(gt), fw_ref);
> + xe_gt_err(gt, "runtime resume failed (%pe)\n", ERR_PTR(err));
> +
> + return err;
> +}
> +
> struct xe_hw_engine *xe_gt_hw_engine(struct xe_gt *gt,
> enum xe_engine_class class,
> u16 instance, bool logical)
> diff --git a/drivers/gpu/drm/xe/xe_gt.h b/drivers/gpu/drm/xe/xe_gt.h
> index 41880979f4de..3f793230e78a 100644
> --- a/drivers/gpu/drm/xe/xe_gt.h
> +++ b/drivers/gpu/drm/xe/xe_gt.h
> @@ -51,6 +51,8 @@ int xe_gt_suspend(struct xe_gt *gt);
> void xe_gt_shutdown(struct xe_gt *gt);
> int xe_gt_resume(struct xe_gt *gt);
> void xe_gt_reset_async(struct xe_gt *gt);
> +int xe_gt_runtime_resume(struct xe_gt *gt);
> +int xe_gt_runtime_suspend(struct xe_gt *gt);
> void xe_gt_sanitize(struct xe_gt *gt);
> int xe_gt_sanitize_freq(struct xe_gt *gt);
>
> diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
> index 433abc787f7b..f4f55027dd7a 100644
> --- a/drivers/gpu/drm/xe/xe_guc.c
> +++ b/drivers/gpu/drm/xe/xe_guc.c
> @@ -1618,6 +1618,22 @@ void xe_guc_stop_prepare(struct xe_guc *guc)
> }
> }
>
> +void xe_guc_pause(struct xe_guc *guc)
> +{
> + xe_guc_submit_pause(guc);
> + xe_guc_ct_stop(&guc->ct);
> + xe_guc_ct_disable(&guc->ct);
Note that xe_guc_ct_stop and xe_guc_ct_disable do more or less the same
thing, with the main difference being that the _stop() discards any
pending messages, while the _disable() throws an error about them.
We hold an rpm ref when there are pending messages, so if we're rpm
suspending there should be no pending messages; if there are any, that's
a bug and we want to catch the issue and not just ignore it. Therefore,
for the rpm suspend call we shouldn't call xe_guc_ct_stop. IMO it's
probably also worth renaming this function to xe_guc_runtime_suspend,
because there might be other scenarios where we do want to discard
pending messages so we don't want this to be a too generic function.
> + guc->submission_state.enabled = false;
Should probably set this before xe_guc_ct_disable (that way it's also
symmetrical with the resume path)
> +}
> +
> +void xe_guc_unpause(struct xe_guc *guc)
> +{
> + guc_enable_irq(guc);
> + xe_guc_ct_state_enable(&guc->ct);
> + guc->submission_state.enabled = true;
> + xe_guc_submit_unpause(guc);
> +}
> +
> void xe_guc_stop(struct xe_guc *guc)
> {
> xe_guc_ct_stop(&guc->ct);
> diff --git a/drivers/gpu/drm/xe/xe_guc.h b/drivers/gpu/drm/xe/xe_guc.h
> index 22cf019a11bf..6385159d1711 100644
> --- a/drivers/gpu/drm/xe/xe_guc.h
> +++ b/drivers/gpu/drm/xe/xe_guc.h
> @@ -51,6 +51,8 @@ void xe_guc_reset_wait(struct xe_guc *guc);
> void xe_guc_stop_prepare(struct xe_guc *guc);
> void xe_guc_stop(struct xe_guc *guc);
> int xe_guc_start(struct xe_guc *guc);
> +void xe_guc_pause(struct xe_guc *guc);
> +void xe_guc_unpause(struct xe_guc *guc);
> void xe_guc_declare_wedged(struct xe_guc *guc);
>
> static inline u16 xe_engine_class_to_guc_class(enum xe_engine_class class)
> diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
> index 3f4e6a46ff16..283d7631a940 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ct.c
> +++ b/drivers/gpu/drm/xe/xe_guc_ct.c
> @@ -465,6 +465,14 @@ static void ct_exit_safe_mode(struct xe_guc_ct *ct)
> xe_gt_dbg(ct_to_gt(ct), "GuC CT safe-mode disabled\n");
> }
>
> +void xe_guc_ct_state_enable(struct xe_guc_ct *ct)
Given that this is more or less the opposite of xe_guc_ct_disable, IMO
it'd be clearer to name this one xe_guc_ct_enable and rename the
existing xe_guc_ct_enable to something else (xe_guc_ct_register ?)
Note that I've only looked this from a GuC POV, not from a full GT
perspective.
Daniele
> +{
> + guc_ct_change_state(ct, XE_GUC_CT_STATE_ENABLED);
> +
> + if (ct_needs_safe_mode(ct))
> + ct_enter_safe_mode(ct);
> +}
> +
> int xe_guc_ct_enable(struct xe_guc_ct *ct)
> {
> struct xe_device *xe = ct_to_xe(ct);
> @@ -489,14 +497,11 @@ int xe_guc_ct_enable(struct xe_guc_ct *ct)
> if (err)
> goto err_out;
>
> - guc_ct_change_state(ct, XE_GUC_CT_STATE_ENABLED);
> + xe_guc_ct_state_enable(ct);
>
> smp_mb();
> wake_up_all(&ct->wq);
>
> - if (ct_needs_safe_mode(ct))
> - ct_enter_safe_mode(ct);
> -
> #if IS_ENABLED(CONFIG_DRM_XE_DEBUG)
> /*
> * The CT has now been reset so the dumper can be re-armed
> diff --git a/drivers/gpu/drm/xe/xe_guc_ct.h b/drivers/gpu/drm/xe/xe_guc_ct.h
> index 18d4225e6502..34ad8c31c4ad 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ct.h
> +++ b/drivers/gpu/drm/xe/xe_guc_ct.h
> @@ -17,6 +17,7 @@ int xe_guc_ct_enable(struct xe_guc_ct *ct);
> void xe_guc_ct_disable(struct xe_guc_ct *ct);
> void xe_guc_ct_stop(struct xe_guc_ct *ct);
> void xe_guc_ct_fast_path(struct xe_guc_ct *ct);
> +void xe_guc_ct_state_enable(struct xe_guc_ct *ct);
>
> struct xe_guc_ct_snapshot *xe_guc_ct_snapshot_capture(struct xe_guc_ct *ct);
> void xe_guc_ct_snapshot_print(struct xe_guc_ct_snapshot *snapshot, struct drm_printer *p);
> diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
> index 51ed7270994a..9a306b5fbdaa 100644
> --- a/drivers/gpu/drm/xe/xe_pm.c
> +++ b/drivers/gpu/drm/xe/xe_pm.c
> @@ -495,7 +495,7 @@ int xe_pm_runtime_suspend(struct xe_device *xe)
> }
>
> for_each_gt(gt, xe, id) {
> - err = xe_gt_suspend(gt);
> + err = xe->d3cold.allowed ? xe_gt_suspend(gt) : xe_gt_runtime_suspend(gt);
> if (err)
> goto out_resume;
> }
> @@ -558,7 +558,7 @@ int xe_pm_runtime_resume(struct xe_device *xe)
> xe_irq_resume(xe);
>
> for_each_gt(gt, xe, id)
> - xe_gt_resume(gt);
> + xe->d3cold.allowed ? xe_gt_resume(gt) : xe_gt_runtime_resume(gt);
>
> xe_display_pm_runtime_resume(xe);
>
> diff --git a/drivers/gpu/drm/xe/xe_uc.c b/drivers/gpu/drm/xe/xe_uc.c
> index 465bda355443..ac2910ce027d 100644
> --- a/drivers/gpu/drm/xe/xe_uc.c
> +++ b/drivers/gpu/drm/xe/xe_uc.c
> @@ -15,6 +15,7 @@
> #include "xe_guc.h"
> #include "xe_guc_pc.h"
> #include "xe_guc_engine_activity.h"
> +#include "xe_guc_submit.h"
> #include "xe_huc.h"
> #include "xe_sriov.h"
> #include "xe_uc_fw.h"
> @@ -301,6 +302,24 @@ int xe_uc_suspend(struct xe_uc *uc)
> return xe_guc_suspend(&uc->guc);
> }
>
> +void xe_uc_runtime_suspend(struct xe_uc *uc)
> +{
> + /* GuC submission not enabled, nothing to do */
> + if (!xe_device_uc_enabled(uc_to_xe(uc)))
> + return;
> +
> + xe_guc_pause(&uc->guc);
> +}
> +
> +void xe_uc_runtime_resume(struct xe_uc *uc)
> +{
> + /* GuC submission not enabled, nothing to do */
> + if (!xe_device_uc_enabled(uc_to_xe(uc)))
> + return;
> +
> + xe_guc_unpause(&uc->guc);
> +}
> +
> /**
> * xe_uc_declare_wedged() - Declare UC wedged
> * @uc: the UC object
> diff --git a/drivers/gpu/drm/xe/xe_uc.h b/drivers/gpu/drm/xe/xe_uc.h
> index 21c9306098cf..5398da1a8097 100644
> --- a/drivers/gpu/drm/xe/xe_uc.h
> +++ b/drivers/gpu/drm/xe/xe_uc.h
> @@ -14,6 +14,8 @@ int xe_uc_init_post_hwconfig(struct xe_uc *uc);
> int xe_uc_load_hw(struct xe_uc *uc);
> void xe_uc_gucrc_disable(struct xe_uc *uc);
> int xe_uc_reset_prepare(struct xe_uc *uc);
> +void xe_uc_runtime_resume(struct xe_uc *uc);
> +void xe_uc_runtime_suspend(struct xe_uc *uc);
> void xe_uc_stop_prepare(struct xe_uc *uc);
> void xe_uc_stop(struct xe_uc *uc);
> int xe_uc_start(struct xe_uc *uc);
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